<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>JavaScript语句是对浏览器的命令</title>
</head>

<body>
    <h2>JavaScript语句</h2>
    <p><b>JavaScript 程序</b> 是一系列由计算机执行的 <b>语句</b>。</p>
    <p id="demo"></p>
    <script>
        var x, y, z;  // 语句 1
        x = 22;        // 语句 2
        y = 11;        // 语句 3
        z = x + y;    // 语句 4
        document.getElementById("demo").innerHTML =
            "z 的值是" + z + "。";
    </script>
</body>

</html>